Charity is the theological virtue that means to love and protect everything and anything in God's world. In this instance the Nice man is helping out a random stranger by giving him money so that the poor homeless man can buy some food and water, so that he isn't extremely hungry.
Wow, that man looks poor and homeless
I feel really bad, I think I should help him?
Here is $50 dollars, buy yourself some food and water, and have a nice day!
Even the smallest kind gestures can show love to the people that God made. In this example a random person can make someone's day.